div {
    margin:10px;
    padding:5px;
}
#father {
    border:1px #000 solid;
}

.layer01 {
    border:1px #F00 dashed;
    display: inline-block;
    float: left;
}
.layer02 {
    border:1px #00F dashed;
    display: inline-block;
    float: left;
}
.layer03 {
    border:1px #060 dashed;
    display: inline-block;
    float: right;
}
/*
clear: right; 右侧不允许有浮动元素
clear: left;  左侧不允许有浮动元素
clear: both;  两侧不允许有浮动元素
clear: none;
*/
.layer04 {
    border:1px #666 dashed;
    font-size:12px;
    line-height:23px;
    display: inline-block;
    float: right;
}